 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.decorators;

 import java.net.URL ;

 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.jface.resource.ImageDescriptor;
 import org.eclipse.jface.viewers.IDecoration;
 import org.eclipse.jface.viewers.ILabelProviderListener;
 import org.eclipse.jface.viewers.ILightweightLabelDecorator;
 import org.eclipse.ui.internal.util.BundleUtility;

 /**
  * The DeclarativeDecorator is a decorator that is made entirely from an XML
  * specification.
  */
 public class DeclarativeDecorator implements ILightweightLabelDecorator {
  
     private String iconLocation;

     private IConfigurationElement configElement;

     private ImageDescriptor descriptor;

     DeclarativeDecorator(IConfigurationElement definingElement, String iconPath) {
         this.iconLocation = iconPath;
         this.configElement = definingElement;
     }

     /**
      * @see org.eclipse.jface.viewers.IBaseLabelProvider#addListener(org.eclipse.jface.viewers.ILabelProviderListener)
      */
     public void addListener(ILabelProviderListener listener) {
     }

     /**
      * @see org.eclipse.jface.viewers.IBaseLabelProvider#dispose()
      */
     public void dispose() {
         //Nothing to do here
 }

     /**
      * @see org.eclipse.jface.viewers.IBaseLabelProvider#isLabelProperty(java.lang.Object,
      * java.lang.String)
      */
     public boolean isLabelProperty(Object element, String property) {
         return false;
     }

     /**
      * @see org.eclipse.jface.viewers.IBaseLabelProvider#removeListener(org.eclipse.jface.viewers.ILabelProviderListener)
      */
     public void removeListener(ILabelProviderListener listener) {
     }

     /**
      * @see org.eclipse.jface.viewers.ILightweightLabelDecorator#decorate(java.lang.Object,
      * org.eclipse.jface.viewers.IDecoration)
      */
     public void decorate(Object element, IDecoration decoration) {
         if (descriptor == null) {
             URL url = BundleUtility.find(configElement.getDeclaringExtension()
                     .getNamespace(), iconLocation);
             if (url == null) {
                 return;
             }
             descriptor = ImageDescriptor.createFromURL(url);
         }
         decoration.addOverlay(descriptor);
     }
 }

